Prof. Tyler Cowen interviews Prof. Raj Chetty…

……If we look at your papers, they’re about topics people have already thought about. The data work is completely state of the art, but I don’t think it would be said you’re doing something other people can’t do, and yet several times a year, you come out with papers of great import that make a big splash, and the results seem to hold up. So what in fact is your competitive advantage? [laughs]

CHETTY: That’s a tough question. Part of what we try to do is exactly as you said: take old questions. I think some of the most important questions in economics and social science have not yet been fully answered, and the recent availability of big data of various types allows us, for the first time, to tackle those classic questions. What our research group tries to do is bring those two things together.

COWEN: But those both sound replicable, right? What’s the non-replicable asset?

CHETTY: What hopefully our contribution and scale is, is showing how you can take those large datasets and not get lost in them, and bring out the key lessons that are relevant for thinking about these classic questions.

It’s very easy — students often have this reaction, that all I need to do is get access to this big dataset, and then I’m going to be all set for my thesis. And what you end up finding is that that is often not the case. It’s very easy to write a paper that is not that good, even with cutting-edge data and modern techniques. So one of the things that I try to do — and the easiest way to see this is if you internally, within our research group, see the iterations of the papers we’ve been working on — where we start out is often very far away from the papers that people see as the finished product. We work hard to try to write a paper that ex post seems extremely simple: “Oh, it’s obvious that that’s the set of calculations you should have done.”